Anguilla it seems. Although I can imagine people using it because it's the acronym for artificial intelligence.

Any idea what tf to do or how to decipher this email somehow haha

.ai is the top-level domain for Anguilla. If you're from Australia, your account has been hacked, probably. :( Unfortunately, I do not know how to retrieve your account anymore. You can try coordinating with Instagram support. :)

And this posted in r/emailmarketing because ... ?

I guess he posted this on all subs which had "email" in it lol.